/**
 * #      1254
 * 名称   统计封闭岛屿的数目
 * 链接   https://leetcode-cn.com/problems/number-of-closed-islands
 * 题解   [165](https://leetcode-cn.com/problems/number-of-closed-islands/solution)
 * 通过率 59.1%
 * 难道   中等
 */

